Polymeric fibers containing color concentrates

ABSTRACT

Color concentrates for coloring polymeric materials, which comprise 
     A. colorant, 
     B. deflocculating agent, and 
     C. polymeric carrier.

CROSS-REFERENCE TO RELATED APPLICATIONS

This is a divisional of application Ser. No. 414,287 filed Nov. 9, 1973,now U.S. Pat. No. 3,905,937 which is a continuation-in-part ofapplication Ser. No. 241,253, filed Apr. 5, 1972, now abandoned.

BACKGROUND OF THE INVENTION

This invention relates to color concentrates for preparing coloredsynthetic fibers. It is more particularly directed to color concentratescontaining unique deflocculating agents.

It is well known that synthetic fibers, particularly polyester fibers,are difficult and expensive to dye dark shades. To produce such darksynthetic fibers, it has been the practice in years past to add apigment such as carbon black during the polymerization process. Whenthis is done, the pigment is carried into the fiber-forming polymeritself, and consequently into the fiber.

This method has produced satisfactory fibers, but pigment added this waytends to quickly clog filters, particularly the sand-pack filterslocated before the spinning apparatus. Besides this, because of thenature of the process, the entire polymerization and spinning trainbecomes contaminated with pigment, or with dye if a dye is used, and ifthis equipment is then used to manufacture fiber of a different color,the whole apparatus must first be cleaned.

Repacking filters and cleaning apparatus mean that equipment lies idlewhile it is being worked on and this in turn means economic loss.

The color concentrates of this invention minimize these disadvantages.According to the invention, a color concentrate is added after thefiber-forming polymer has been prepared, so there is less equipment toclean. In addition, the color concentrate stabilizes the pigment so thatthere is far less filter clogging. For example, when carbon black isincorporated into a polyester fiber according to the invention, ordinarycommercial sand-pack filters can be in continuous use for in excess of18 days, while the same filter, used in a conventional process, clogs tothe point of uselessness in only 4 days.

In addition to this, use of the color concentrates of the inventionprovides a fiber much less prone to break in winding-up or texturing.

The color concentrates provide all these advantages and, as a bonus,give fibers with more brilliant and stable colors than those fibersconventionally produced.

SUMMARY OF THE INVENTION

The Color Concentrates

The color concentrates of the invention ordinarily contain threeingredients -- colorant, deflocculating agent and carrier polymer.

1. The colorant can be a pigment, a dye (soluble or insoluble in thesystem) such as dihydroxy-bis-arylamino anthraquinones andcyanobenzene-azoanilines, or mixtures of these.

Illustrative pigments are TiO₂, carbon black, zinc oxide, antimonyoxide, titanates, phthalocyanines, quinacridones, isoindolenes,perylenes and silicates. Mixtures of these can also be used to getdesired colors.

Concentrates of the invention can also be made with fire retardantagents such as antimony oxide or zinc oxide, optical brighteners andreinforcing agents such as asbestos.

These additives are ordinarily present in the concentrates atconcentrations of from about 1% through about 80% by weight of the totalconcentrate, preferably from about 20% through about 40 %. Theconcentration will of course depend on the type of additive being use,the effect desired, the nature of the fiber-forming polymer and likefactors.

In some cases, it may be desirable to use from 1 through 10% or 1through 15% of additive, sometimes 10 through 15%, or 10 through 20%.Similarly, it may be desirable to use from 40 through 50%, from 50through 60%, or even 60 through 70% of certain additives. In any case,the final concentration can be easily determined by one skilled in thisart using well-known principles of pigmentation.

2. Speaking broadly, the deflocculating agent can be any, or a mixtureof any, polymeric materials of the type having the general structure##EQU1## where

A is a segment bearing one or more functional groups capable of beingadsorbed on the particle surface;

Z is an organic linking radical, which in some cases may be absent;

B is a polymeric segment, the same as, or compatible with, thefiber-forming polymer;

m and n are 1, 2, 3 or 4, the total not exceeding 4.

By "compatible" is meant that there be no phase separation on amicroscopic scale.

Illustrative of classes of deflocculating agents which can be used are:

CLASS I

Addition polymers represented by the structure ##EQU2## where

R₁, R₂ and R₄ can be hydrogen, alkyl radicals of 1 through 4 carbonatoms, --CH₂ CH₂ NH₂ radicals, or --CH₂ CH₂ OH radicals;

R₃ and X can be hydrogen or alkyl radicals of 1 through 4 carbon atoms;

Z_(b) can be an organic linking radical;

Y can be hydrogen, an alkyl radical of 1 through 4 carbon atoms, analkenyl radical of 2 through 6 carbon atoms, --CN, halogen, phenyl,--OR, ##EQU3## or ##EQU4## where R is an alkyl radical of 1 through 18carbon atoms;

D can be an end group such as hydrogen, alkyl or alkenyl;

a can be a number 1 through 2000;

b can be 0 or 1; and

c can be a number 5 through 5000;

the c/a quotient being greater than 1.

CLASS II

Polyesters represented by the structure ##EQU5## where

R₁, R₂ and R₄ can be hydrogen, alkyl radicals of 1 through 4 carbonatoms, --CH₂ CH₂ NH₂, or --CH₂ CH₂ OH;

R₃ can be hydrogen or an alkyl radical of 1 through 4 carbon atoms;

Z_(b) can be a divalent organic linking radical;

B can be a polyester or copolyester segment, number average molecularweight 500-50,000, preferably 1000-20,000.

a can be a number 1 through 2000; and

b is 0 or 1.

The Class II deflocculating agents preferred for use are ##SPC1####SPC2##

CLASS III

Polyesters represented by the structure ##SPC3##

where

R₁, R₂, R₃ and R₄ can be hydrogen or --COOH (provided at least one ofR₁, R₂, R₃ or R₄ is --COOH);

R₅ can be R₆ OOC-- or ##SPC4##

where R₆ can behydrogen,H--C--(CH₂)₁₀ COOH|(CH₂)₅|CH₃--CH₂ COOHCH₃--CH₃--C∠HCH₃----CH₂ ----₁₁ CH₃CH₂ CH₂ OH--CH₂ CH₂ N∠CH₂ CH₂ OH--CH₂ CH₂ SCH₂CH₃--CH₂ Ch₂ CH₂ COOHCH₃|--C--COOH|CH₃CH₃ OH H|--C----COOH --C--C--COOH|HCOOH COOH--CH₂ CH₂ COOH∠N--CH₂ CH₂ N∠HOOCCH₂ CH₂COOHN∥--C|∠SC∠HOOCNorOH|--CH₂ ----C----COOHH ₄andZ can beO∥--C--,--CH₂--,--S--,--SO₂ -- or --O--;

and B can be ##EQU6## where

X and Y can be phenylene or alkylene radicals of 2 through 18 carbonatoms;

D can be a phenyl or straight- or branched chain alkyl radical of 1through 18 carbon atoms; and

n is a number 10 through 500.

CLASS IV

Polyesters represented by the structures ##EQU7## where

R can be the residue from a polyhydroxy compound;

A can be ##SPC5## or ##SPC6##

where

R₁, R₂, R₃ and R₄ can be hydrogen or --COOH; and

Z can be ##EQU8## --CH₂ --, --S--, --O--, or --SO₂ --;

X can be phenylene or an alkylene radical of 2 through 18 carbon atoms;

Y can be an alkylene radical of 2 through 18 carbon atoms;

D can be phenyl or a straight- or branched chain alkyl radical of 1through 18 carbon atoms;

a can be a number 2 through 6; and

n can be a number 10 through 500.

CLASS V

Polyesters represented by the structure ##EQU9## where

G can be the residue of a basic radical which, as an entity beforereaction, has a pk_(a) value of 5-14, or a salt thereof;

R can be alkylene of 2 through 36 carbon atoms, phenylene, tolylene,##EQU10##

B can be a segment of a polyester or copolyester having a number averagemolecular weight of 500-50,000, preferably 1000-20,000; and

a can be 1, 2 or 3.

The Class V deflocculating agents preferred for use are ##EQU11####SPC7##

CLASS VI

Polyesters represented by the structure ##EQU12## where

A can be a radical bearing at least two hydroxyl groups such as##EQU13##

Z can be an organic linking radical;

X can be an alkylene radical of 2 through 18 carbon atoms;

D can be hydrogen or an alkyl radical of 1 through 18 carbon atoms; and

n can be a number 10 through 500.

CLASS VII

Polymeric materials represented by the structure ##EQU14## where

B can be a polymeric segment of ethylenically unsaturated monomerslacking Zerewitinoff hydrogen atoms (nummber average molecular weight500-100,000 preferably 1000-10,000);

X can be the residue of a chain transfer agent;

Y can be the residue of di-, tri- or tetraisocyanate radical;

A can be the residue of an acid radical having a pk_(a) value of -1 to6; and

m and n can be 1, 2 or 3, the total not exceeding 4.

Where n is 2 or 3, only one of A need be as defined.

Deflocculating agents of Class VII preferred for use are those where Ais a mercapto-, hydroxy- or carboxy substituted carboxylic acid radical.Especially preferred are those materials where A is ##EQU15##

The Class VII deflocculating agents also preferred are those where X is

    --S--R--D

where R is alkylene of 1-6 carbon atoms, and ##EQU16##

Also preferred are those Class VII deflocculating agents wherein Y is##EQU17##

The Class VII deflocculating agent most preferred for use is thatrepresented by the structure ##EQU18##

where B is a methyl methacrylate/2-ethyl hexyl acrylate copolymericsegment.

CLASS VIII

Polymeric materials represented by the structure ##EQU19## where

B can be a polymeric segment, number average molecular weight of500-100,000, preferably 1000-10,000, of ethylenically unsaturatedmonomers lacking Zerewitinoff hydrogen atoms;

X can be the residue of a chain transfer agent;

Y can be the residue of a di-, tri-, or tetraisocyanate radical;

A can be the residue of a mercapto-, hydroxy-, or aminoalkyl alkoxysilane radical; and

m and n are 1, 2 or 3 (the total not exceeding 4).

Where n is 2 or 3, only one of A need be as defined.

CLASS IX

Polymeric materials represented by the structure ##EQU20## where

B can be a polymeric segment, number average molecular weight500-100,000, preferably 1000-10,000, of ethylenically unsaturatedmonomers lacking Zerewitinoff hydrogen atoms;

X can be the residue of a chain transfer agent;

Y can be the residue of a di-, tri-, or tetraisocyanate radical;

A can be the residue of a basic radical which as an entity beforereaction has a pk_(a) value of 5-14, or a salt thereof, and

m and n can be 1, 2 or 3 (the total not exceeding 4).

When n is 2 or 3, only one of A need be as defined.

CLASS X

Polyesters represented by the structure ##EQU21## where

A is an acid radical having a pk_(a) value of -1 to 6;

Y is the residue of a di-, tri- or tetraisocyanate radical;

B is a polyester or copolyester segment (number average molecular weight500-50,000, preferably 1000-10,000); and

m and n are 1, 2 or 3 (the total not exceeding 4).

Where m is 2 or 3, only one of A need be as defined.

The Class X material preferred for use is ##EQU22##

The deflocculating agents are ordinarily present in the colorconcentrates at concentrations of from about 1 through about 25% byweight of the total concentrate, preferably from about 5 through about12%. Lesser amounts than this generally confer no particular advantage.Larger amounts have no adverse effect on deflocculation, but mayadversely affect fiber quality.

The goal is to get maximum deflocculation without affecting the physicalproperties of the fiber. In certain cases one may therefore use lessthan 1% of the deflocculating agent with satisfactory result, or he mayuse more than 25%, for example, up to 35% or even 40% by weight of thetotal concentrate. 1% to 4% may be adequate in some cases -- 12% to 15%may be preferred in some instances, and 15% to 20% or even 15% to 25% or15% to 30% may be satisfactory in particular cases.

The pigment/deflocculating agent weight ratio should be 1-10/1.

The deflocculating agents described in formulas (1) through (18) can beprepared according to the directions in Belgian Pat. No. 767,376.

3. The polymeric carriers used in the color concentrates of theinvention are ordinarily the same as, or of the same type as, thefiber-forming polymer. This, of course, is the preferred system. Shoulda different carrier be necessary for one reason or another, it can beused with satisfactory results if it is compatible with thefiber-forming polymer, "compatible", as before, meaning no phaseseparation on a microscopic scale. Mixtures of carriers can be used.

The carrier polymer is present in the concentrate at a concentrationwhich is arrived at by difference, that is, one first determines thetotal amount of concentrate to be made, calculates the amount of pigmentthe concentrate is to contain, and then computes the amount ofdeflocculating agent needed to adequately disperse this amount ofpigment in the concentrate. The difference betwen the total of pigmentand agent is made up with carrier polymer. Ordinarily these polymericcarriers will constitute from 40% to about 98% by weight of the totalconcentrate.

Although one ordinarily uses a polymeric carrier for the concentrates,it may in some instances be desirable to use liquid materials such asreactive monomers, plasticizers and the like, provided of course thatthey are compatible with the fiber-forming polymer.

How the Color Concentrates are Made

The concentrates of the invention are made by first mixing suitableamounts of pigment and deflocculating agent, and then sand grinding orball or pebble milling this mixture for from 4 to 8 hours.

A solution of a suitable carrier polymer is then prepared in acompatible solvent. Illustrative of such solvents are toluene, xylene,methylene chloride and tetrachloroethylene. The concentration of thecarrier polymer in this solution can range from about 5% to about 70%,by weight, preferably about 15% to 40%.

The pigment dispersion and solution of carrier polymer are thoroughlymixed and the mixture dried by spraying, by extrusion, by evaporation orby drying on a rotary drier. For ease of handling, the dry material canthen be converted into pellets, flakes or powder by conventional means.

The Fiber-forming Polymer

The color concentrates of the invention will ordinarily be used in thepreparation of colored polyester fibers. Saturated polyesters andcopolyesters such as polyethylene glycol terephthalate/isophthalate andpolyethylene glycol terephthalate can be used.

The concentrates can also be used to prepare colored fibers of acrylicpolymers such as polyacrylonitrile, polyamides, polyolefins andpolycaprolactones.

These concentrates can also be used to color polymers used in molding orextrusion, such as ABS resins, polystyrenes, aminoplast resins,unsaturated polyesters, polyvinyl chloride, polyvinylidene chloride, andrubbers such as polybutadiene, polyisoprene and ethylene/propylene/dienerubbers.

How Fibers of the Invention are Made

The fibers can be prepared by two basic techniques, melt-injection andflake blending.

In the drawings,

FIG. 1 is a diagrammatic representation of the melt-injection method. Inthis method molten fiber-forming polymer is passed to a mixer into whichmolten color concentrate is metered by means of a metering pump, havingbeen first melted in a screw melter or equivalent apparatus.

After the molten fiber-forming polymer and color concentrate have beenthoroughly mixed, the mixture is passed to a conventional spinningapparatus, where it is spun into fiber.

FIG. 2 is a diagrammatic representation of the flake-blending method ofpreparing fibers.

In this system, fiber-forming polymer flake and color concentrate flakeare mixed in suitable proportions in a dry blend mixer. The mixture isthen melted in a screw melter or equivalent apparatus and is then passedto a spinning apparatus where it is spun into fiber.

In either system, the color concentrate, be it in the form of a melt ora flake, is metered into the molten fiber-forming polymer stream or ismixed with the fiber-forming polymer flake in proportions to provideabout 0.05-5% preferably 2% by weight of pigment in the final fiber.

In either of these methods, the selections of times, temperatures, andprocess details will be dictated by the type of polymer being used, thekind of pigment employed, the solvents used, and like factors. In anycase, these things will be readily apparent or can be easily worked outby one skilled in this art, using well-known principles of engineering.

PREFERRED EMBODIMENTS OF THE INVENTION

The following Examples are submitted so that the invention may be morereadily understood and practiced.

Those skilled in the art will no doubt be able to compose numerousvariations on their central theme, such as the attachment of innocuoussubstituents to the deflocculating agent molecules. These variations areconsidered a part of the invention.

In the Examples all parts are by weight unless otherwise indicated.

EXAMPLE 1

A. Four parts of a 62.5% (by weight) solution in toluene of ##EQU23##were mixed with another 20 parts of toluene.

Five parts of carbon black were then slowly added to this solution withthorough mixing. The mixture was then sand-ground to give a dispersioncontaining 26% solids, 17.25% pigment.

B. One hundred parts of Polycaprolactone 700* were dissolved in 113parts of toluene. To this solution were then added, with mixing, 263parts of the pigment dispersion in (A).

C. The dispersion in (B) was dried in a vented twin screw,counter-rotating extruder to give strands of concentrate. These werethen chopped into 1/8 inch pellets, and dried in a vacuum oven overnightat 50°C.

D. An appropriate amount of this color concentrate was screw melted andmetered at a precalculated rate into a molten polyester stream¹ beingspun into fiber at the rate of 10 lbs./hr. The resulting fiber,uniformly jet black, contained 2% by weight, of pigment.

EXAMPLE 2

                               Parts                                              ______________________________________                                        (A)  Perylene Red 6818.sup.2                                                                             23%                                                     Indo Brilliant Scarlet R-6500.sup.3                                                                 70%       15                                            Quinacridone RT-201-D.sup.4                                                                          7%                                                     Solution of Deflocculating                                                    Agent of Example 1              12                                            and                                                                           Toluene                         48                                       were processed as in Example 1(A).                                            ______________________________________                                         .sup.2 Holland-Suco Co., Holland, Michigan.                                   .sup.3 Allied Chemical Co.                                                    .sup.4 E. I. du Pont de Nemours & Co.                                    

B. Polyester¹, 36.7 parts, was dissolved in 146.8 parts of methylenechloride. To this solution was then added, with mixing, 84.4 parts ofthe pigment dispersion of (A).

C. The mixture prepared in (B) was stirred vigorously for 5 hours at50°C. The resulting gel was pan dried in a vacuum oven overnight, thetemperature in the oven being gradually increased from room temperatureto 100°C. The dry material was then frozen in dry ice, crushed and fedinto a molten polyester stream as in Example 1 to give a red fiber,containing about 2% pigment.

EXAMPLE 3

The mixture of colorants in part (A) of Example 2 was replaced with

    Phthalocyanine Blue BT-465-D.sup.2                                                                   55%                                                    Quinacridone RT-201-D.sup.3                                                                          35%                                                    Carbon Black           10%                                                    A color concentrate was prepared as in Example 2 and                          similarly processed to give a blue fiber.                                      .sup.2 and .sup.3 E. I. du Pont de Nemours & Co.                         

I claim:
 1. A polymeric fiber containing enough of a compositioncomprising, as essential components,A. colorant, 1-80% by weight; B.1-25% by weight of a deflocculating agent of Class I through Class X;and C. a polymeric carrier, not of Class I through Class X in (B),compatible with the fiber-forming polymer,to provide 0.05-5%, by weightof the fiber, of colorant.
 2. A polymeric fiber according to claim 1wherein the deflocculating agent in (B) is of Class II, Class V or ClassX.
 3. A polymeric fiber according to claim 2 wherein the colorant iscarbon black, the carrier is a polyester and the deflocculating agent isof formula (3), (4), (9), (10), (11) or (18).
 4. A method for preparinga colored polymeric fiber, the method comprisingA. putting thecomposition described in claim 1 into liquid form, B. metering enough ofthe composition into a stream of molten polymer to provide 0.05-5%, byweight of the polymer, of colorant, C. mixing the composition and thepolymer, and then D. spinning the polymer.
 5. The method of claim 4wherein the fiber-forming polymer is a polyester and the composition isdescribed in claim
 2. 6. The method of claim 4 wherein the fiber-formingpolymer is a polyester and the composition is described in claim
 3. 7. Amethod for preparing a colored polymeric fiber, the method comprisingA.putting the composition described in claim 1 into solid form, B.blending enough of the composition with solid fiber-forming polymer toprovide 0.05-5%, by weight of the polymer, of colorant C. melting themixture, and then D. spinning the mixture.
 8. The method of claim 7wherein the fiber-forming polymer is a polyester and the concentrate isdescribed in claim
 2. 9. The method of claim 8 wherein the fiber-formingpolymer is a polyester and the concentrate is described in claim 3.